1. Field of the Invention
The present invention relates to a plate-type hinge device for a display for a rotation type mobile phone comprising main and sub-display devices.
2. Description of the Related Art
Generally, the term “mobile communication terminals” refer to mobile phones or handheld devices used for mobile wireless communications. The mobile communication terminals are classified into a bar type, a flip type and a folder type according to their construction. A bar-type mobile terminal has a bar-shaped single housing. A flip-type mobile terminal has a bar-shaped housing and a flip rotatably connected to the housing by a hinge. A folder-type mobile terminal has a bar-shaped housing and a folder rotatably connected to the housing by a hinge.
Recently, new designs such as a rotation (or swing) type and a slide type have been developed to meet the diverse needs and tastes of users. The rotation type has a pair of facing housings, one of which is rotatable on the other housing. The slide type has a pair of housings, one of which slides in relation to the other housing in a longitudinal direction to open or close the terminal. Such diverse types of mobile communication terminals are easily understandable by those skilled in the relevant art.
Mobile communication terminals with small and light designs have gained popularity for their improved portability. These small and light terminals are more convenient during a voice call or video-conference.
As illustrated in FIGS. 1 to 3, a conventional mobile phone in display rotation type comprises a main housing 10 with a first hinge axis Al, a folder 20 and a connection member 30. The main housing 10 is provided with a plurality of key buttons 11 and a microphone 12. The connection member 30 connects the folder 20 to the main housing 10 in such a manner that the folder 20 can rotate around the first hinge axis Al in a direction to be closer to or away from the front surface of the main housing 10. The connection member 20 has a second hinge axis A2 around which the folder 20 can rotate in contact with the connection member 20. The folder 20 comprises an LCD 21 and speakers 22.
The connection member 30 also has a hinge module 40 mounted therein to make the folder 20 rotatable around the second hinge axis A2.
To better view moving images, video or mobile game images, a user can rotate the display device of the folder 20 in a direction providing a wider display (i.e., a landscape display mode).
However, such a conventional rotation type mobile phone has a single display device on the internal surface of the folder. When the folder is closed, the display device cannot be used. If an additional display device is provided on the external surface of the folder, the size and thickness of the hinge module is increased, an undesirable side effect in light of consumer demand for smaller and lighter terminals. In addition, such an additional display device will limit design variations and improvements for mobile phones.